U.S. patent number 5,276,675 [Application Number 07/629,305] was granted by the patent office on 1994-01-04 for optical disk cartridge assembly.
This patent grant is currently assigned to Hewlett-Packard Company. Invention is credited to Thomas C. Oliver, Robert D. Proctor, Mark E. Wanger.
United States Patent |
5,276,675 |
Wanger , et al. |
January 4, 1994 |
Optical disk cartridge assembly
Abstract
An optical disk cartridge assembly comprising: an optical disk
for storing data thereon in machine readable form; a casing for
rotatably supporting the optical disk therewithin and for shielding
the optical disk from physical contact with other objects; and a
door slideably mounted on the casing for selectively covering and
uncovering an opening therein; the casing having a wear factor
associated with sliding contact with the door of less than in
100.times.10.sup.-10 in..sup.3 -min./ft.-lb.-hr. and most
preferably less than 10.times.10.sup.-10 in..sup.3
-min./ft.-lb.-hr. An information storage system employing a
low-wear optical disk cartridge assembly and a method of making a
low-wear optical disk cartridge assembly are also disclosed.
Inventors: |
Wanger; Mark E. (Fort Collins,
CO), Proctor; Robert D. (Loveland, CO), Oliver; Thomas
C. (Fort Collins, CO) |
Assignee: |
Hewlett-Packard Company (Palo
Alto, CA)
|
Family
ID: |
24522443 |
Appl.
No.: |
07/629,305 |
Filed: |
December 18, 1990 |
Current U.S.
Class: |
720/726; 360/133;
720/744; G9B/17.054; G9B/23.038; G9B/23.042; G9B/23.046 |
Current CPC
Class: |
G11B
17/225 (20130101); G11B 23/0326 (20130101); G11B
23/0315 (20130101) |
Current International
Class: |
G11B
23/03 (20060101); G11B 17/22 (20060101); G11B
023/03 () |
Field of
Search: |
;369/36,37,38,39,291,292
;360/133,92 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
US. patent application Ser. No. 314,012 filed Feb. 22, 1989 for
Cartridge Handling System of Mark Elliot Wanger et al. (HP Docket
188434). .
Brochure entitled: Lubricomp Internally Lubricated Reinforced
Thermoplastics and Fluoropolymer Composites Bulletin 254,688, from
LNP, Santa Ana, Calif..
|
Primary Examiner: Shepperd; John
Assistant Examiner: Kessell; Michael C.
Claims
What is claimed is:
1. An optical disk cartridge assembly comprising:
optical disk means for storing data thereon in machine readable
form;
casing means for rotatably supporting said optical disk means
therewithin and for shielding said optical disk means from physical
contact with other objects; and
door means slideably mounted on said casing means for selectively
covering and uncovering an opening therein;
said casing means having a wear factor associated with sliding
contact with said door means of less than 100.times.10.sup.-10
in.sup.3 -min/ft-lb-hr; and
said casing means being constructed from a thermoplastic material
impregnated with a lubricating filler, wherein said lubricating
filler comprises at least 15% by weight of said casing means.
2. The invention of claim 1 said casing means having a wear factor
associated with sliding contact with said door means of less than
10.times.10.sup.-10 in.sup.3 -min/ft-lb-hr.
3. The invention of claim 1 said thermoplastic material comprising
at least one of: ABS plastic, SAN plastic, and polycarbonate
plastic.
4. The invention of claim 1 said lubricating filler comprising at
least one of:
polytetrafluoroethylene (PTFE), and silicone.
5. The invention of claim 4 said casing material being at least 15%
by weight PTFE.
6. An information storage assembly comprising:
a) an optical disk cartridge assembly comprising:
i) optical disk means for storing data thereon in machine readable
form;
ii) casing means for rotatably supporting said optical disk means
therewithin and for shielding said optical disk means from physical
contact with other objects; and
iii) door means slideably mounted on said casing means for
selectively covering and uncovering an opening therein;
b) an optical disk reading means for slideably receiving said
optical disk cartridge assembly therein and for reading data from
said optical disk means;
c) cartridge storage cell means for storing said optical disk
cartridge assembly during periods when said cartridge assembly is
not inserted in said optical disk reading means;
d) mechanized cartridge handling means for engaging said cartridge
assembly and for moving said cartridge assembly between said
cartridge storage cell means and said optical disk reading
means;
said casing means having a wear factor associated with sliding
contact with said door means and with sliding contact with any
engaged surface of said optical disk reading means, said cartridge
storage cell means, and said mechanized cartridge handling means of
less than 350.times.10.sup.-10 in.sup.3 -min/ft-lb-hr;
said casing means being constructed from a thermoplastic material
impregnated with a lubricating filler, wherein said lubricating
filler comprises at least 15% by weight of said casing means.
7. The invention of claim 6 said casing means having a wear factor
associated with sliding contact with said door means and with
sliding contact with any engaged surface of said optical disk
reading means, said cartridge storage cell means, and said
mechanized cartridge handling means of less than
100.times.10.sup.-10 in.sup.3 -min/ft-lb-hr.
8. The invention of claim 6 said thermoplastic material comprising
at least one of: ABS plastic, SAN plastic, and polycarbonate
plastic.
9. The invention of claim 6, said lubricating filler comprising at
least one of:
polytetrafluoroethylene (PTFE), and silicone.
10. The invention of claim 9 said casing means being at least 15%
by weight PTFE.
11. A method of producing an optical disk cartridge assembly
comprising the steps of:
a) constructing a casing door;
b) constructing a cartridge casing from a thermoplastic material
impregnated with a lubricating filler which is at least 15% by
weight of the casing, said casing having a wear factor, associated
with sliding contact with said casing door, of less than
100.times.10.sup.-10 in.sup.3 -min/ft-lb-hr;
c) rotatably mounting an optical disk within said cartridge
casing.
12. The invention of claim 11 wherein said step of constructing a
cartridge casing comprises using a casing material having a wear
factor associated with sliding contact with said casing door, of
less than 10.times.10.sup.-10 in.sup.3 -min/ft-lb-hr.
13. The invention of claim 11 wherein said step of constructing a
cartridge casing comprises using a casing material which is at
least 15% by weight PTFE.
14. An optical disk cartridge assembly comprising:
optical disk means for storing data thereon in machine readable
form;
casing means for rotatably supporting said optical disk means
therewithin and for shielding said optical disk means from physical
contact with other objects; and
door means slideably mounted on said casing means for selectively
covering and uncovering an opening therein;
said casing means having a wear factor associated with sliding
contact with said door means of less than 100.times.10.sup.-10
in.sup.3 -min/ft-lb-hr; and
said casing means being constructed from a thermoplastic material
impregnated with a reinforcing filler which reduces friction
comprising at least 30% by weight of said casing means.
15. The invention of claim 14, said casing means being at least 30%
by weight carbon fiber.
16. An information storage assembly comprising:
a) an optical disk cartridge assembly comprising:
i) optical disk means for storing data thereon in machine readable
form;
ii) casing means for rotatably supporting said optical disk means
therewithin and for shielding said optical disk means from physical
contact with other objects; and
iii) door means slideably mounted on said casing means for
selectively covering and uncovering an opening therein;
b) an optical disk reading means for slideably receiving said
optical disk cartridge assembly therein and for reading data from
said optical disk means;
c) cartridge storage cell means for storing said optical disk
cartridge assembly during periods when said cartridge assembly is
not inserted in said optical disk reading means;
d) mechanized cartridge handling means for engaging said cartridge
assembly and for moving said cartridge assembly between said
cartridge storage cell means and said optical disk reading
means;
said casing means having a wear factor associated with sliding
contact with said door means and with sliding contact with any
engaged surface of said optical disk reading means, said cartridge
storage cell means, and said reading means, said cartridge storage
cell mans, and said mechanized cartridge handling means of less
than 350.times.10.sup.-10 in.sup.3 -min/ft-lb-hr;
said casing means being constructed from a thermoplastic material
impregnated with a reinforcing filler which reduces friction, said
reinforcing filler which reduces friction comprising at least 30%
by weight of said casing means.
17. The invention of claim 16, said casing means being at least 30%
by weight carbon fiber.
18. A method of producing an optical disk cartridge assembly
comprising the steps of:
a) constructing a casing door;
b) constructing a cartridge casing from a thermoplastic material
impregnated with a reinforcing filler which reduces friction, said
reinforcing filler which reduces friction comprising at least 30%
by weight of said casing, said casing having a wear factor,
associated with sliding contact with said casing door, of less than
100.times.10.sup.10 in.sup.3 -min/ft-lb-hr; and
c) rotatably mounting an optical disk within said cartridge
casing.
19. The invention of claim 18, wherein said step of constructing a
cartridge casing comprises using a casing material which is at
least 30% by weight carbon fiber.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to an optical disk
cartridge assembly and, more particularly to an optical disk
cartridge assembly provided with a low wear casing.
An optical disk is a data storage medium which is readable by a
laser-based reading device. Optical disks known as "compact disks"
or "CDs" have become increasing popular during the past few years
for recording music and audio-video works. Due to the huge storage
capacity of optical disks as compared to conventional magnetic
storage media, optical disks known as "ROM disks" have become
popular for storing computer readable information. However, until
very recently, optical disks were of somewhat limited use in the
computer industry due to the fact that optical disks could not be
"erased" and "written" with new information, i.e. ROM disks are
"read only" memory devices. However, recent technology has produced
optical disks which are both computer readable and computer
writable. Thus, in the future, optical disks are expected to become
increasingly more important in the computer industry and may
eventually replace magnetically readable and writable storage media
such as "floppy disks" and "hard disks." Another recent
development, the ability to provide data storage on both surfaces
of an optical disk, has effectively doubled the optical disk
storage capacity.
Optical disks of the type used in computer applications are
generally provided in a cartridge assembly including an optical
disk, a parallelepiped-shaped casing in which the disk is rotatably
mounted, and a sliding reader door which selectively covers or
uncovers an opening in the casing to shield or expose the disk. An
optical disk reading/writing device or "optical drive" generally
receives a cartridge assembly through a narrow slot provided on the
front face of the device. Typically, the cartridge being inserted
initially abuttingly engages a biased door in the device and is
urged against the door to open it. The cartridge casing then slides
over a supporting surface within the reading/writing device as it
is pushed into the device. After the cartridge has been loaded into
the device, a locating pin within the device is inserted through a
transversely extending hole on the cartridge casing to hold the
cartridge in a fixed position within the device. Prior to
reading/writing, a mechanism within the device slides open the
cartridge door to expose the disk to a laser.
Currently, most optical disks are hand-inserted into drives.
However, for large databases consisting of many optical disks, it
is preferable, and perhaps essential, to provide an optical disk
storage system for storing the disks at known locations, and an
optical disk handling system which is capable of retrieving a
desired disk from a storage location and inserting the disk into an
optical disk drive.
U.S. patent application Ser. No. 314,012 filed Feb. 22, 1989, of
Wanger et al. for CARTRIDGE HANDLING SYSTEM, now U.S. Pat. No.
5,010,536, is hereby specifically incorporated by reference for all
that it discloses. This patent discloses a disk storage and
retrieval system or "autochanger" wherein the stored disks and an
associated disk reader are arranged in a longitudinally extending,
two-dimensional array consisting of vertically extending columns
and laterally extending rows. This autochanger system is adapted to
engage a disk, move it vertically, laterally, and/or longitudinally
and then release it in order to remove it from storage, move it
into aligned relationship with the disk reader, and insert it into
the disk reader. The disk handling system is also adapted to flip
the disk to reverse the side thereof which will be positioned in
readable relationship with a reader. The system is further adapted
to reorient a disk at the time it is initially inserted into the
system by an operator.
Cartridge casings are subject to wear as a result of surface
contact made with other objects Wear rate is generally defined as
the volumetric loss of material over a unit time. A "wear factor"
may be defined in terms of parameters which affect wear rate. "Wear
factor", as used herein, is defined as follows:
K (wear factor)=W/FVT, where:
W=volume wear (in.sup.3)
F=force (lb)
V=velocity (ft/min)
T=elapsed time (hr)
The wear factors for various materials as specified herein are
based upon wear factor measurements made in accordance with a
procedure described at p. 25 of a brochure entitled: LUBRICOMP
INTERNALLY LUBRICATED REINFORCED THERMOPLASTICS AND FLUOROPOLYMER
COMPOSITES Bulletin 254,688, which is available from LNP (a
business unit of ICI Americas, Inc.), 1831 E. Carnegie, Santa Ana,
Calif., 92705, which is hereby specifically incorporated by
reference for all that it discloses and which is set forth in
Appendix A which forms a part of the disclosure of this
application.
Currently, most optical disk casings are constructed from a
thermoplastic material such as polycarbonate which has a wear
factor "K" on the order of 2500.times.10.sup.-10 in.sup.3
-min/ft-lb-hr. It is applicants' discovery that such currently used
casing material creates a problem in optical disk cartridge
assemblies which are used in autochangers such as described in U.S.
patent application Ser. No. 314,012 and such as are currently sold
under the product designation C1710 by Hewlett-Packard Company
having a business address of 3000 Hanover Street, Palo Alto,
Calif., 94304. Applicants have discovered that in such autochangers
abrasive wear of cartridge casings causes a build up of fine
particles in the autochanger optical drives which contaminates the
surface of optical disks, thus effecting the reading or writing
operation being performed, and which also may cause jamming of the
cartridge door and jamming of other malfunctions of the optical
drives or various other mechanical assemblies of the autochanger.
Applicants have discovered that this particle build up is produced
by frictional engagement of the cartridge with various surfaces of
cartridge storage cells, the optical drive(s), and the cartridge
handling mechanism of the autochanger, as well as by the sliding
movement of the reader doors of cartridges. These problems
associated with abrasive wear of cartridges used in autochangers
were to applicants' knowledge not know in the art prior to
applicants' discovery.
SUMMARY OF THE INVENTION
The present invention is directed to solving the problem of
autochanger malfunction. It is applicants' discovery that one cause
of autochanger malfunction is the build up of particulate matter
within autochanger drives and other system components and that the
cause of this particulate matter build up is abrasive contact
between the surfaces of currently used optical disk cartridge
casings and the reader doors of the cartridges and also the
abrasive contact between the cartridge casings and the various
surfaces of the autochanger system with which the cartridges make
contact.
Applicants have solved this problem by providing a cartridge casing
which has a wear factor which is sufficiently low so as to avoid
particulate build up of a magnitude which would significantly
adversely effect the operation of an autochanger.
Thus, the invention may comprise an optical disk cartridge assembly
comprising an optical disk for storing data thereon in machine
readable form; a casing for rotatably supporting the optical disk
therewithin and for shielding the optical disk from physical
contact with other objects; and a door slideably mounted on the
casing for selectively covering and uncovering an opening therein;
the casing having a wear factor associated with sliding contact
with the door of less than 100.times.10.sup.-10 in..sup.3
-min./ft.-lb.-hr. and most preferably less than 10.times.10.sup.-10
in..sup.3 -min./ft.-lb.-hr.
The invention may also comprise an information storage assembly.
The information storage assembly includes an optical disk cartridge
assembly comprising an optical disk for storing data thereon in
machine readable form; a casing for rotatably supporting the
optical disk therewithin and for shielding the optical disk from
physical contact with other objects; and a door slideably mounted
on the casing for selectively covering and uncovering an opening
therein. The information storage assembly also includes an optical
disk reading device for slideably receiving the optical disk
cartridge assembly therein and for reading data from the optical
disk; a cartridge storage cell for storing the optical disk
cartridge assembly during periods when the cartridge assembly is
not inserted in the optical disk reading device; and a mechanized
cartridge handling device for engaging the cartridge assembly and
for moving the cartridge assembly between the cartridge storage
cell and the optical disk reading device. The casing has a wear
factor associated with sliding contact with the door and with
sliding contact with any engaged surface of the optical disk
reading device, the cartridge storage cell, and the mechanized
cartridge handling device of less than 350.times.10.sup.-10
in..sup.3 -min./ft.-lb.-hr. and most preferably less than
100.times.10.sup.-10 in..sup.3 -min./ft.-lb.-hr.
The casing may be constructed from a thermoplastic material
impregnated with at least one of: polytetrafluoroethylene (PTFE),
silicone, glass fiber and carbon fiber. The thermoplastic material
may comprise at least one of: ABS plastic, SAN plastic, and
polycarbonate plastic. In one preferred embodiment the casing is
constructed from a thermoplastic material impregnated with carbon
fiber wherein the carbon fiber at least 30% by weight. In another
preferred embodiment the casing is constructed from a thermoplastic
material impregnated with PTFE wherein the PTFE is at least 15% by
weight.
The invention may also comprise a method of producing an optical
disk cartridge assembly including the steps of constructing a
casing door; constructing a cartridge casing from a material having
a wear factor, associated with sliding contact with the casing
door, of less than 100.times.10.sup.-10 in..sup.3
-min./ft.-lb.-hr.; and rotatably mounting an optical disk within
the cartridge casing.
BRIEF DESCRIPTION OF THE DRAWINGS
Illustrative and presently preferred embodiments of the invention
are shown in the accompanying drawings in which:
FIG. 1 is a schematic side elevation view of an optical disk
cartridge handling system.
FIG. 2 is a schematic front elevation view of an optical disk
cartridge handling system.
FIG. 3 is a perspective view of an optical disk cartridge
assembly
FIG. 4 is a schematic, cut away, side elevation view of a portion
of an optical disk reading apparatus and optical disk cartridge
assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
Autochanger Assembly
FIGS. 1 and 2 illustrate an optical disk cartridge handling system
10 for use in association with a plurality of longitudinally
extending, rearwardly opening, cartridge holding units which
include storage cells 12, 14, 16, etc. and disk reading/writing
devices or optical drives 15, 17 arranged in a laterally and
vertically extending holding unit array 20. The handling system 10
and holding unit array 20, sometimes referred to herein
collectively as an "autochanger assembly" or simply "autochanger",
is provided within a closed housing 18 having a front wall 23, a
back wall 25, a top wall 27, a bottom wall 29, a left lateral side
wall 31, and a right lateral side wall 33. An intermediate housing
wall 35 may be positioned between the front and back walls for
separating electronic and motor components from other components of
the apparatus.
The handling system 10 may comprise an insertion means 21 for
receiving a cartridge 24 which is hand-inserted by a human operator
with a first end of the cartridge positioned forwardly. The
insertion means longitudinally and rotationally displaces the
cartridge so as to present the cartridge to a cartridge engaging
means with the first end of the cartridge positioned towards the
rear of the housing.
A cartridge engaging means 22 is provided for engaging an exposed
end portion of a cartridge positioned in the insertion means 21 or
in another aligned holding unit, e.g. 12, 14, 16.
A longitudinal displacement means 26 is operatively associated with
the engaging means for longitudinally displacing a cartridge 24
engaged by the engaging means 22.
A flipping means 28 is operatively associated with the engaging
means 22 and is used for invertingly rotating a cartridge engaged
by the engaging means about a longitudinally extending flip axis
DD.
A lateral displacement means 30 is operatively associated with the
engaging means 22 for laterally displacing a cartridge 24 engaged
by the engaging means.
A rotatable first drive means 32 is drivingly linked to the
longitudinal displacement means 26, the flipping means 28, and the
lateral displacement means 30 for providing driving force
thereto.
Stop means 34 may be provided which limit the movement of the
longitudinal displacement means 26.
A flip latch means 36 is provided which has a latched state and an
unlatched state and which is operatively associated with the
flipping means 28 for preventing rotation thereof when the flip
latch means 36 is in the latched state.
A translation latch means 38 is provided which has a latched state
and an unlatched state. The translation latch means is operatively
associated with the lateral displacement means 30 for preventing
lateral displacement thereof when the translation latch means is in
the latched state.
The cartridge handling system 10 has a longitudinally displacing
operating state wherein the stop means 34 is in disengaged
relationship with the longitudinal displacement means 26; the flip
latch means 36 is in its latched state; and the translation latch
means 38 is in its latched state. The cartridge handling system 10
comprises a rotatably flipping operating state wherein the stop
means 34 is in engaged relationship with the longitudinal
displacement means 26; the flip latch means 36 is in its unlatched
state; and the translation latch means 38 is in its latched state.
The cartridge handling system 10 also comprises a laterally
displacing operating state wherein the translation latch means 38
is in its unlatched state.
A first gear means 40 (22, 36, 4170, 4172) is provided which is
mounted in rotationally displaceable relationship with the lateral
displacement means 30 and which is drivingly linked to the
longitudinal displacement means 26 and the flipping means 28.
A continuous drive belt means 42 is provided which is continuously
nonslippingly engaged with the first gear means 40 for drivingly
linking the first gear means 40 with the first drive means 32. The
continuous belt means may comprise a first portion 44 extending in
a first lateral direction from the first gear means 40 and a second
portion 46 extending in a second lateral direction from the first
gear means. The lateral displacement means 30 is laterally
displaceable through movement of the continuous belt means 42 when
the first gear means 40 is locked against rotation.
A gear lock means 48 having a locked state and an unlocked state is
provided which is operatively associated with the first gear means
40. The gear lock means 48 prevents rotation of the first gear
means 40 when the gear lock means is in its locked state. The
cartridge handling system 10 is constructed and arranged such that
the gear lock means 48 is in its locked state when the translation
latch means 38 is in its unlatched state, and such that the gear
lock means 48 is in its unlocked state when the translation latch
means 38 is in its latched state.
The optical disk cartridge handling system 10 also comprises a
vertical displacement means 50 for vertically displacing a
cartridge 24 engaged by the cartridge engaging means 22. A second
drive means 52 is operatively associated with the vertical
displacement means 50 for providing driving force thereto.
Optical Disk Cartridge Assembly
An optical disk cartridge assembly 24 is shown in FIG. 3. Cartridge
assembly 24 has a rear end portion 64 which is adapted to be
inserted into an optical disk reading device, e.g. 15, and has a
forward end portion 66 which is adapted to ordinarily be grasped by
a human operator for inserting and removing the cartridge from an
optical disk reading device.
The cartridge assembly includes an optical disk 70, a casing 72
within which the optical disk is rotatably mounted, and a reader
door 74 which is slideably mounted on the casing 72. The reader
door is slidingly displaceable, as indicated at 75 to cover or
uncover an opening 76 in the casing so as to enable a reading or
writing laser beam within an optical drive to impinge upon the
optical disk. The reader door is biased in the closed position and
is openingly displaceable by a mechanism (not shown) within an
optical drive. The reader door may be constructed from steel or
other material and may be fabricated and mounted on the casing by
conventional techniques known in the art.
The cartridge casing 72 is generally parallelepiped shaped having
generally flat top 80, bottom 82, rear 84, front 86, and lateral
88, 90 exterior surfaces. The casing may be constructed from a
separate top section 92 and bottom section 94 which may be
individually injection molded using conventional molding techniques
well known in the art. The top and bottom sections meet at seam
line 96 and are held together as by screws (not shown) or other
conventional means well known in the art. The top and bottom
sections 92, 94 define an enclosure within which the optical disk
70 is conventionally rotatably mounted.
One or more holes 98 are provided which extend transversely through
the casing and which are adapted to receive a pin portion 118 of
the optical drive for registering the cartridge with the drive as
described in further detail below. The casing is also provided with
vertically extending channels 102, 104 in its lateral sidewalls
near the front end 66 thereof for enabling the cartridge to be
engaged and moved by the cartridge handling system 10.
FIG. 4 schematically illustrates portions of an optical disk drive
15 (which may be a Sony Model SMO-D501-01 Optical Disk Drive which
is commercially available from Hewlett-Packard Company having a
business address of 3000 Hanover Street, Palo Alto, Calif., 94304.
The drive 15 comprises a spring biased, normally vertically
disposed, hinged door 110 which is adapted to be urged into the
open position illustrated in phantom in FIG. 4 by the rear end 84
of a cartridge casing during insertion of the cartridge in the
drive 15. The drive door 110 is typically constructed from
polycarbonate. One or more horizontal support rails 112 are
provided within the drive for slideably engaging and supporting the
cartridge casing at the bottom surface 82 thereof. The support
rails 112 are typically constructed from steel. At least one
vertically extendable registration pin assembly 116 is provided
within the drive which is adapted to extend a registration pin 118
from a raised position, as shown in solid lines, to a lowered
position as shown in phantom. The pin 118 is extended after the
cartridge is inserted into the optical drive and passes through
hole 98 in the cartridge casing so as to hold the cartridge in a
fixed registration position with the optical drive. The pin 118
sometimes makes contact with the casing surface defining hole 98 as
it is inserted.
During initial insertion of an optical disk cartridge assembly into
the disk handling apparatus 10, the cartridge casing makes contact
at the rear and bottom surface portions thereof with portions of
the insertion apparatus 21 which may comprises parts made primarily
from polyethersulfone (PES). The cartridge 24 is subsequently
removed from the insertion apparatus by engagement of the cartridge
by fingers of engagement means 22 at its vertical channel portions
102, 103 and is sliding moved across a horizontal surface of
longitudinal displacement means 26. Both the fingers of engagement
means 22 and the horizontal surface of displacement means 26 may be
constructed from nylon. The cartridge 26 is next slidingly inserted
into a drive, e.g. 15, or a storage cell, e.g. 14. The storage
cells may have cartridge support surfaces constructed from
polycarbonate.
The material from which the cartridge casing is constructed has a
wear factor of preferably less than 350.times.10.sup.-10 in.sup.3
-min/ft-lb-hr, and most preferably less than 100.times.10.sup.-10
in.sup.3 -min/ft-lb-hr, with respect to each surface in the
autochanger with which the cartridge makes frictional contact. The
material from which the cartridge casing is constructed has a wear
factor of preferably less than 100.times.10.sup.-10 in.sup.3
-min/ft-lb-hr and most preferably less than 10.times.10.sup.-10
in.sup.3 -min/ft-lb-hr with respect to the reader door.
In one preferred embodiment of the invention the cartridge casing
is constructed from thermoplastic material which has been
impregnated with a lubricating filler including at least one of:
polytetrafluoroethylene (PTFE), silicone. The cartridge casing may
also be constructed from thermoplastic material which has been
impregnated with a reinforced filler which also lowers friction
such as carbon fiber. The thermoplastic material from which the
cartridge casing is constructed is preferably one of: ABS plastic,
SAN plastic, and polycarbonate plastic.
The cartridge casing is most preferably constructed from a
thermoplastic material impregnated with carbon fiber in which the
amount of carbon fiber by weight is at least 30% of the total
weight of the casing material or impregnated with PTFE in which the
amount of PTFE by weight is at least 15% of the total weight of the
casing material. The casing materials described in this paragraph
are commercially available from a number of sources, including LNP
Engineering Plastics, 1831 E. Carnegie, Santa Ana, Calif.,
92705.
By using casing materials as specifically described above, the
resulting optical disk cartridge may typically be loaded into an
autochanger optical disk drive in excess of 100,000 times before a
drive jamming failure caused by casing wear is encountered. Optical
disk cartridges using conventional casing material typically cause
drive jamming due to casing wear after less than 5,000 drive
loads.
While an illustrative and presently preferred embodiment of the
invention has been described in detail herein, it is to be
understood that the inventive concepts may be otherwise variously
embodied and employed and that the appended claims are intended to
be construed to include such variations except insofar as limited
by the prior art.
* * * * *